Caster wheels for a portable appliance

ABSTRACT

A portable appliance such as a washing maching or the like is supported on a frame which is mounted on two pairs of casters. A first pair of casters is located at adjacent corners of the frame and each of this pair has its pintle mounted substantially vertically with respect to the frame. The other pair of casters is mounted at the other corners of the frame and their pintles are supported at a substantial angle to the vertical, whereby the first pair of casters is free to swivel about their respective pintles but the second pair of casters is substantially restrained from swiveling by the weight of the appliance, but the wheels are free to move linearly.

United States Patent [191 Weir et al.

[451 May 20, 1975 CASTER WHEELS FOR A PORTABLE APPLIANCE [73] Assignee: Whirlpool Corporation, Benton Harbor, Mich.

22 Filed: ,Nov.23, 1973 21 Appl. No.: 418,376

[52] US. Cl 280/79.1; 16/35 [51] Int. Cl B62b 1/12;B60b 33/00 [58] Field of Search 280/79.1, 79.2, 79.3; 16/35, 35 D; 68/3 R [56] References Cited UNITED STATES PATENTS 918,819 4/1909 Bowers 280/79.2 X 1,649,946 11/1927 Brostedt 280/79.1 X 3,416,682 12/1968 Pezzutti 16/35 R X Primary ExaminerDavid Sc honberg Assistant Examiner-Michael .l. Forman Attorney, Agent, or Firm-Hill, Gross, Simpson, Van Santen, Steadman, Chiara & Simpson [57] ABSTRACT A portable appliance such as a washing maching or the like is supported on a frame which is mounted on two pairs of casters. A first pair of casters is located at adjacent comers of the frame and each of this pair has its pintle mounted substantially vertically with respect to the frame. The other pair of casters is mounted at the other corners of the frame and their pintles are supported at a substantial angle to the vertical, whereby the first pair of casters is free to swivel about their respective pintles but the second pair of casters is substantially restrained from swiveling by the weight of the appliance, but the wheels are free to move linearly.

6 Claims, 4 Drawing Figures PATENTED HAYZOIQYS 3, 884.493

SHEET 10F 2 Fig. 2

PATENTED HAYZO I975 3,884,493

sum 2 OF 2 CASTER WHEELS FOR A PORTABLE APPLIANCE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention is in the field of portable appliance structures supported on two sets of casters, one set of which is permitted to swivel freely while the other is restrained from swiveling movement, thereby inhibiting objectionable machine movement during dynamic operation of the appliance while permitting a desired degree of machine movement, upon the application of pushing forces.

2. Description of the Prior Art Portable appliances, particularly portable washing machines are subject to the difficulty that their portability leads to instability during dynamic operation of the machine. For example, in a portable automatic washing machine during the high speed spin or drum braking cycles, there is a tendency for the washer to move along the floor if it is merely supported on conventional sets of caster wheels. In order to overcome this objectionable movement, it has been suggested as in U.S. Pat. No. 3,635,491 owned by the assignee of the present application to provide a caster jack mechanism which is operated by means of a foot pedal to support the appliance on the caster wheels during movement, but retract the caster wheels during operation of the machine. An improvement on thattype of apparatus is disclosed in U.S. Pat. No. 3,673,592 also owned by the assignee of the present application wherein an electrical system is provided to prevent energization of the appliance when the cabinet is elevated and supported on the caster wheels, as well as to afford a signal.

There are some examples in the prior art of caster assemblies having offset axes for various purposes. For example, in Jones U.S. Pat. No. 2,370,355, there is a disclosure of a side delivery rake in which the rear caster wheel is laterally tilted so that it trails on an angle to the line of advance of the rake and thus tends to resist the side draft and cause the rear end of the rack to swing outwardly to its normal operating posi' tion.

Orelind et al. U.S. Pat. No. 2,433,148 describes a plow with means for changing the mounting of the rear furrow wheel so that it will not caster on forward or rearward movement of the plow when in an operating position, but permits the wheel to caster on forward movement of the plow when the plow is in a transport position. I

Ferwerda U.S. Pat. No. 2,560,562 describes a caster wheel assembly with movable means provided above the center of swing of the caster for limiting and controlling the caster movement.

Glass U.S. Pat. No. 3,124,922 describes a side delivery rake including a spring-biased caster mounted at an angle to the frame such that when the rake is lifted from the ground, the caster wheel is held by its spring in the position it assumed at the time the rake was lifted.

Gerth U.S. Pat. No. 3,727,245 describes a rollable collapsible bed supported on a set of barrel-shaped casters which are offset from their swiveling axis to facilitate rolling movement in a direction at right angles to the length of the bed even if the casters are misaligned.

SUMMARY OF THE INVENTION The present invention provides an improved caster assembly for supporting a portable appliance in which two of the caster wheels are freely rotatable through an arc of 360 and in which the other two are held in the frame with the axes of their pintles at a substantial angle to both the vertical and horizontal directions so that in order for the second pair of casters to swivel, the weight of the machine must be removed from the axes of their pintles. Consequently, the frame resists movement during dynamic operation of the appliance, but the appliance can be moved along a floor surface by pushing a top edge or pushing against the side of the appliance. Thus, in the case of a portable washing machine, the machine can be operated for washing and spin operations while supported on the casters without undue movement of the washer.

One of the features of the present invention consists in providing mounting means in the frame which will accept identical swiveling casters, the front mounting means providing for a substantially vertical alignment of the spindle axes, and the rear mounting means providing for the required angular orientation of the spindle axes. Since the casters may all be identical, they can be readily installed by the installer without fear of a mixup in installing the front and rear casters.

The caster assembly of the present invention is useful for various types of portable appliances but finds particular use in conjunction with a portable washer in which the bulk of the mass is supported on a series of spaced springs. This type of spring suspension system has a tendency to accentuate the tendency of the appliance to move along the floor particularly if there is an unbalanced load in the machine undergoing a high speed operation.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects, features and advantages of the invention will be readily apparent from the following description of certain preferred embodiments thereof, taken in conjunction with the accompanying drawings, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure, and in which:

FIG. 1 is a view in perspective, partly broken away, of a portable washing machine embodying the improvements of the present invention;

FIG. 2 is a fragmentary view in elevation, also partially broken away, illustrating the manner in which the casters are received within the base frame of the machine;

FIG. 3 is a plan view of the base frame assembly; and

' FIG. 4 is a fragmentary view of a single caster assembly to illustrate the structure more completely.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 10 indicates generally a portable washing machine including a cabinet having a front wall 11, side walls 12 and 13 and a rear wall 14. The cabinet also includes a top 15 in which there is a pivotally mounted access door 16.

Within the enclosure of the cabinet, there is an imperforate tub 17 in which there is mounted a perforate basket 18 in which the clothes to be washed are located during agitation and spinning of the load. A vertical axis agitator 19 is provided for oscillatory movement within the perforate basket 18. Various cycles of the automatic washing machine are under the control of a selector knob 20 which, with an associated timer mechanism, programs the machine through its various cycles in the conventional manner.

A sub-frame 21 is disposed below the combination of the tub 17 and the perforate basket 18. Beneath the sub-frame 21 are disposed a motor 22 and a pump 23 which is driven by the motor 22.

The mass of the tub 17, the basket 18, the agitator l9 and the drive mechanism is carried by the sub-frame 21 and supported by providing brackets 24 attached to the sub-frame 21, and interposing a plurality of springs 25 between the brackets 24 and a base frame 26 forming the bottom closure of the machine. The details of the spring suspension system are not germane to the present invention, and they have been described and claimed in the copending application, Ser. No. 325,983, assigned to the assignee of the present invention. It will suffice to say that there is a tendency in spring suspended machines to accentuate the problem of movement along the support floor during dynamic operation of the machine, particularly during high speed cycles. The support system of the present invention is therefore particularly applicable to such spring suspended machines.

As best illustrated in FIGS. 2, 3 and 4, the base frame 26 is provided with downwardly inclined portions 26a and 26b in the vicinity of the rear corners of the base frame. U-shaped brackets 27 and 28 are fixedly secured to the inclined portions 26a and 26b, respectively, and receive therethrough pintles 29 and 30 of the caster wheel assemblies. All of the caster wheel assemblies can be identical for the purposes of the present invention and include bifurcated arms such as arms 31 which are connected to a caster wheel 32 by means of pins 33. Each of the pintles, such as pintle 29, has an enlarged medial portion 290 which passes freely through an aperture in the inclined portion 26a but is retained by the smaller diameter aperture in the bracket 27 so that a snap-in connection is provided between the caster wheel assembly and the bracket.

At the forward end of the cabinet, another pair of inverted U-shaped brackets 34 and 35 are provided and are secured to horizontally extending portions 260 and 26d of the base frame. The brackets 34 and 35 receive pintles 36 and 37 of the same configuration as described in conjunction with pintle 29. For example, pintle 36 carries a bifurcated arm 38 which supports a caster wheel 39 by means of a pin 40. Since the axes of pintles 36 and 37 are substantially vertical, however, the associated caster wheels are free to rotate through an arc of 360 as illustrated by the dash line showing in FIG. 2.

The caster assemblies at the front of the machine are thus capable of swiveling movement while the caster assemblies at the rear of the machine are essentially prevented from swiveling or turning because the weight of the appliance must be lifted to permit free swivel action. These rear casters function as non-swiveling casters to properly limit movement of the washing machine during the spin cycle or braking of the drum. Nevertheless, the arrangement is such that the washer is portable and can be easily rolled along the floor surface by pushing on a top edge or against the side of the washer.

It will thus be understood that the portable appliance of the present invention provides a relatively inexpensive, readily installable caster mechanism for providing portability of the appliance but effectively restraining lateral movement of the appliance during dynamic operation of the washer.

It should be evident that various modifications can be made to the described embodiments without departing from the scope of the present invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

l. A portable appliance for dynamic operation comprising a four-sided frame,

a first pair of casters located at adjacent corners of said frame,

a second pair of casters located at the other corners of said frame,

means supporting said first pair of casters on the frame with their pintles substantially vertically disposed, and

means supporting said second pair of casters on the frame with their pintles at a substantial angle to both the vertical and horizontal directions whereby said first pair of casters is free to swivel about their respective pintles but said second pair of casters is substantially restrained from swiveling movement by the weight of said appliance and limits movement of the appliance during the dynamic operation thereof.

2. An appliance according to claim 1 in which said two pairs of casters are substantially identical in configuration.

3. An appliance according to claim 1, in which said appliance has a plurality of assembled parts supported by a spring suspension system acting against said frame.

4. In a portable appliance including a frame, at least one part rotatably supported on said frame, a motor supported by said frame, and casters carried by said frame to support said appliance on a floor surface, said motor being adapted to place said one part in rotation to create a tendency of the appliance to move on the floor surface, the improvement which comprises:

a first pair of spaced brackets adjoining two corners of the frame for positioning two of said casters with their pintles in substantially vertical disposition, and

'a second pair of brackets at the other two corners of the frame arranged to support the other two casters with their pintles at a substantial angle to both the vertical and horizontal to thereby inhibit swiveling motion of said other two casters and resist the tendency of the appliance to move on the floor surface during rotational movement of said one part.

5. A portable appliance according to claim 4, in which said motor and part are supported by said frame through a plurality of springs.

6. A portable appliance according to claim 4 in which all of said casters are substantially identical in configuration. 

1. A portable appliance for dynamic operation comprising a four-sided frame, a first pair of casters located at adjacent corners of said frame, a second pair of casters located at the other corners of said frame, means supporting said first pair of casters on the frame with their pintles substantially vertically disposed, and means supporting said second pair of casters on the frame with their pintles at a substantial angle to both the vertical and horizontal directions whereby said first pair of casters is free to swivel about their respective pintles but said second pair of casters is substantially restrained from swiveling movement by the weight of said appliance and limits movement of the appliance during the dynamic operation thereof.
 2. An appliance according to claim 1 in which said two pairs of casters are substantially identical in configuration.
 3. An appliance according to claim 1, in which said appliance has a plurality of assembled parts supported by a spring suspension system acting against said frame.
 4. In a portable appliance including a frame, at least one part rotatably supported on said frame, a motor supported by said frame, and casters carried by said frame to support said appliance on a floor surface, said motor being adapted to place said one part in rotation to create a tendency of the appliance to move on the floor surface, the improvement which comprises: a first pair of spaced brackets adjoining two corners of the frame for positioning two of said casters with their pintles in substantially vertical disposition, and a second pair of brackets at the other two corners of the frame arranged to support the other two casters with their pintles at a substantial angle to both the vertical and horizontal to thereby inhibit swiveling motion of said other two casters and resist the tendency of the appliance to move on the floor surface during rotational movement of said one part.
 5. A portable appliance according to claim 4, in which said motor and part are supported by said frame through a plurality of springs.
 6. A portable appliance according to claim 4 in which all of said casters are substantially identical in configuration. 